Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2021 Jun 10;18(12):6312. doi: 10.3390/ijerph18126312

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© 2021 by the authors.

Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

PMC Copyright notice

Origin and transmission of SARS-CoV-2. The virus is believed to be originated from bats and spread to humans through an intermediate host. Human-to-human transmission mainly occurred by respiratory aerosols generated when an infected person sneezes or speeches. Respiratory aerosols can travel to long distances, whereas respiratory droplets settle down on nearby surfaces and represent a possible risk of infection. Basic reproduction number (R0) of the virus is estimated as 3.6. The faecal-oral route of transmission was reported due to the ability of the virus to replicate in the gastrointestinal tract. Within hospital settings, nosocomial infection is also known to occur among healthcare practitioners and hospitalized patients.